The characteristics and optimal treatment of urolithiasis associated with tuberous sclerosis complex

PURPOSE: The most common renal symptoms of tuberous sclerosis complex (TSC) are angiomyolipomas (AMLs) and renal cysts; however, some patients with TSC also develop urolithiasis. We retrospectively investigated the characteristics and treatment of urolithiasis associated with TSC. METHODS: We analyzed 142 patients who met the diagnostic criteria for TSC, of whom 20 (14.1%) had urolithiasis. We compared the patients’ characteristics, urinary specific gravity, urine pH, serum calcium and intact parathyroid hormone in the urolithiasis and non-urolithiasis groups. In the urolithiasis group, the stone characteristics and various treatments were analyzed. RESULTS: The antiepileptic drugs topiramate and zonisamide were more frequently administered to the urolithiasis group than the non-urolithiasis group (P = 0.013, P = 0.048, respectively). The urine specific gravity and urine pH levels were higher in the urolithiasis group than in the non-urolithiasis group (P = 0.005, P = 0.042, respectively). A multivariate logistic regression analysis demonstrated that urine-specific gravity (P = 0.018; odds ratio 1.471; 95% confidence interval 1.098–1.872) was a significant predictor of TSC-associated urolithiasis. Four patients could not receive extracorporeal shock wave lithotripsy due to the risk of bleeding from the AML. CONCLUSION: Patients with TSC who have an increased urine specific gravity, alkaline urine, and a longer administration of topiramate and zonisamide tend to demonstrate an increased risk of developing urolithiasis and therefore such cases require adequate care. If urolithiasis is comorbid with TSC-associated AML, the treatment options are more limited in cases with multiple AMLs around the stone due to an increased risk of hemorrhage.